Flexible liquid-tight metal conduit consists of a plastic jacket and an inner steel sleeve. In use, it is necessary to maintain a low resistance ground path. It is also necessary to maintain the ground, i.e. avoid a short circuit, at high current levels occurring over short intervals. Flexible, non-metallic, liquid-tight conduit is typically an extruded plastic tube.
Typical liquid-tight connectors have several components which must be carefully assembled to affect the desired connection. One such assembly includes a compression nut, a bushing, a ferrule, and a body member or bushing having exterior threads. The assembly operation is carried out in the field and involves the steps of telescoping the compression nut over the end of the conduit, placing the bushing over the end of the conduit, inserting the ferrule into the conduit, sliding the nut and bushing toward the end of the conduit, and then threading or tightening the compression nut onto the body. The assembly procedure is time consuming and must be carried out with care to avoid misalignment of the various parts and consequent leakage.
Another multi-part prior art liquid-tight connector is disclosed in U.S. Pat. No. 6,616,194. The preferred embodiment disclosed in this patent includes a body member or bushing having an integral, rearwardly extending ferrule. A separate sleeve surrounds the ferrule in spaced relation to form a conduit-receiving channel. The sleeve has inwardly bent tangs that bite into the conduit in order to inhibit withdrawal of the conduit. The sleeve is surrounded and held in place by a third cylindrical member or cover that is threaded onto the bushing. All three members require an assembly operation. The forward end of the bushing or body has a threaded neck that receives a washer and snap ring so that the entire connector consists of five separate pieces.
U.S. Pat. No. 6,044,868 discloses a plastic fitting or connector that is specifically designed for use with non-metallic, liquid-tight conduit. The connector is neither intended nor capable of being used with liquid-tight metallic conduit which requires an electrical ground.